请参考 PDF 数据表获取器件具体的封装图。
这款 8 位(八路)同相总线收发器包含两个独立的电源轨;B 端口具有 VCCB,设置为 3.3V;A 端口具有 VCCA,设置为 5V。这样可实现从 3.3V 到 5V 的环境转换,反之亦然。
SN74LVC4245A 器件旨在实现数据总线之间的异步通信。根据方向控制 (DIR) 输入上的逻辑电平,此器件将数据从 A 总线发送至 B 总线,或者将数据从 B 总线发送至 A 总线。输出使能 (OE) 输入可用于禁用器件,这样可有效隔离总线。控制电路(DIR,OE)由 VCCA 供电。
设计人员可将 SN74LVC4245A 器件端子输出切换到正常的全 3.3V 或全 5V 20 端子 SN74LVC4245 器件,而无需重新布局电路板。设计人员可使用 SN74LVC4245A 器件的 2 到 11 和 14 到 23 引脚的数据路径来与传统的 245 端子输出保持一致。
器件型号 | 封装 | 封装尺寸(标称值) |
---|---|---|
SN74LVC4245A | DB (SSOP, 24) | 8.20mm × 5.30mm |
DW(SOIC,24) | 15.40mm × 7.50mm | |
PW(TSSOP,24) | 7.80mm × 4.40mm |
Changes from Revision I (January 2015) to Revision J (December 2022)
PIN | TYPE(1) | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
VCCA | 1 | — | Power supply for side A |
DIR | 2 | I | Direction control |
A1 | 3 | I/O | Transceiver I/O pin |
A2 | 4 | I/O | Transceiver I/O pin |
A3 | 5 | I/O | Transceiver I/O pin |
A4 | 6 | I/O | Transceiver I/O pin |
A5 | 7 | I/O | Transceiver I/O pin |
A6 | 8 | I/O | Transceiver I/O pin |
A7 | 9 | I/O | Transceiver I/O pin |
A8 | 10 | I/O | Transceiver I/O pin |
GND | 11 | — | Ground |
GND | 12 | — | Ground |
GND | 13 | — | Ground |
B8 | 14 | I/O | Transceiver I/O pin |
B7 | 15 | I/O | Transceiver I/O pin |
B6 | 16 | I/O | Transceiver I/O pin |
B5 | 17 | I/O | Transceiver I/O pin |
B4 | 18 | I/O | Transceiver I/O pin |
B3 | 19 | I/O | Transceiver I/O pin |
B2 | 20 | I/O | Transceiver I/O pin |
B1 | 21 | I/O | Transceiver I/O pin |
OE | 22 | I | Output Enable |
VCCB | 23 | — | Power supply for side B |
VCCB | 24 | — | Power supply for side B |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCCA | Supply voltage range | –0.5 | 6.5 | V | |
VI | Input voltage range | A port(2) | –0.5 | VCCA + 0.5 | V |
Control inputs | –0.5 | 6 | |||
VO | Output voltage range | A port(2) | –0.5 | VCCA + 0.5 | V |
IIK | Input clamp current | VI < 0 | –50 | mA | |
IOK | Output clamp current | VO < 0 | –50 | mA | |
IO | Continuous output current | ±50 | mA | ||
Continuous current through each VCCA or GND | ±100 | mA | |||
Tstg | Storage temperature range | –65 | 150 | °C |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCCB | Supply voltage range | –0.5 | 4.6 | V | |
VI | Input voltage range | B port(2) | –0.5 | VCCB + 0.5 | V |
VO | Output voltage range | B port(2) | –0.5 | VCCB + 0.5 | V |
IIK | Input clamp current | VI < 0 | –50 | mA | |
IOK | Output clamp current | VO < 0 | –50 | mA | |
IO | Continuous output current | ±50 | mA | ||
Continuous current through VCCB or GND | ±100 | mA | |||
Tstg | Storage temperature range | –65 | 150 | °C |
PARAMETER | DEFINITION | VALUE | UNIT | |
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | 2000 | V |
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) | 1000 |
MIN | MAX | UNIT | ||
---|---|---|---|---|
VCCA | Supply voltage | 4.5 | 5.5 | V |
VIH | High-level input voltage | 2 | V | |
VIL | Low-level input voltage | 0.8 | V | |
VIA | Input voltage | 0 | VCCA | V |
VOA | Output voltage | 0 | VCCA | V |
IOH | High-level output current | –24 | mA | |
IOL | Low-level output current | 24 | mA | |
TA | Operating free-air temperature | –40 | 85 | °C |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCCB | Supply voltage | 2.7 | 3.6 | V | |
VIH | High-level input voltage | VCCB = 2.7 V to 3.6 V | 2 | V | |
VIL | Low-level input voltage | VCCB = 2.7 V to 3.6 V | 0.8 | V | |
VIB | Input voltage | 0 | VCCB | V | |
VOB | Output voltage | 0 | VCCB | V | |
IOH | High-level output current | VCCB = 2.7 V | –12 | mA | |
VCCB = 3 V | –24 | ||||
IOL | Low-level output current | VCCB = 2.7 V | 12 | mA | |
VCCB = 3 V | 24 | ||||
TA | Operating free-air temperature | –40 | 85 | °C |
THERMAL METRIC(1) | SN74LVC4245A | UNIT | ||
---|---|---|---|---|
DB | PW | |||
24 PINS | ||||
RθJA | Junction-to-ambient thermal resistance | 90.7 | 100.6 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 51.9 | 44.7 | °C/W |
RθJB | Junction-to-board thermal resistance | 49.7 | 55.8 | °C/W |
ψJT | Junction-to-top characterization parameter | 18.8 | 6.8 | °C/W |
ψJB | Junction-to-board characterization parameter | 49.3 | 55.4 | °C/W |
PARAMETER | TEST CONDITIONS | VCCA | MIN | TYP(2) | MAX | UNIT | ||
---|---|---|---|---|---|---|---|---|
VOH | IOH = –100 μA | 4.5 V | 4.3 | V | ||||
5.5 V | 5.3 | |||||||
IOH = –24 mA | 4.5 V | 3.7 | ||||||
5.5 V | 4.7 | |||||||
VOL | IOL = 100 μA | 4.5 V | 0.2 | V | ||||
5.5 V | 0.2 | |||||||
IOL = 24 mA | 4.5 V | 0.55 | ||||||
5.5 V | 0.55 | |||||||
II | Control inputs | VI = VCCA or GND | 5.5 V | ±1 | μA | |||
IOZ(3) | A port | VO = VCCA or GND | 5.5 V | ±5 | μA | |||
ICCA | VI = VCCA or GND, | IO = 0 | 5.5 V | 80 | μA | |||
ΔICCA(4) | One input at 3.4 V, | Other inputs at VCCA or GND | 5.5 V | 1.5 | mA | |||
Ci | Control inputs | VI = VCCA or GND | Open | 5 | pF | |||
Cio | A port | VO = VCCA or GND | 5 V | 11 | pF |
PARAMETER | TEST CONDITIONS | VCCB | MIN | TYP(4) | MAX | UNIT | ||
---|---|---|---|---|---|---|---|---|
VOH | IOH = –100 μA | 2.7 V to 3.6 V | VCC – 0.2 | V | ||||
IOH = –12 mA | 2.7 V | 2.2 | ||||||
3 V | 2.4 | |||||||
IOH = –24 mA | 3 V | 2 | ||||||
VOL | IOL = 100 μA | 2.7 V to 3.6 V | 0.2 | V | ||||
IOL = 12 mA | 2.7 V | 0.4 | ||||||
IOL = 24 mA | 3 V | 0.55 | ||||||
IOZ(2) | B port | VO = VCCB or GND | 3.6 V | ±5 | μA | |||
ICCB | VI = VCCB or GND, | IO = 0 | 3.6 V | 50 | μA | |||
ΔICCB(3) | One input at VCCB – 0.6 V, | Other inputs at VCCB or GND | 2.7 V to 3.6 V | 0.5 | mA | |||
Cio | B port | VO = VCCB or GND | 3.3 V | 11 | pF |
PARAMETER | FROM (INPUT) | TO (OUTPUT) | VCCA = 5 V ± 0.5 V, VCCB = 2.7 V to 3.6 V | UNIT | |
---|---|---|---|---|---|
MIN | MAX | ||||
tPHL | A | B | 1 | 6.3 | ns |
tPLH | 1 | 6.7 | |||
tPHL | B | A | 1 | 6.1 | ns |
tPLH | 1 | 5 | |||
tPZL | OE | A | 1 | 9 | ns |
tPZH | 1 | 10 | |||
tPZL | OE | B | 1 | 10.3 | ns |
tPZH | 1 | 9.8 | |||
tPLZ | OE | A | 1 | 7 | ns |
tPHZ | 1 | 5.8 | |||
tPLZ | OE | B | 1 | 7.7 | ns |
tPHZ | 1 | 7.8 |